Gyro flux valve compass system



R. s. cuRRY, JR

GYRO FLUX' VALVE COMPASS SYSTEMl Filed March 21, 1942 Feb. 5, 1946.

Patented Feb. 5, 1946 2,393,974 GYRO FLUX VALVE CGMPASS SYSTEM Robert S. Curry, Jr., Baldwin,

Sperry Gyroscope Company, Inc.,

a corporation of New York N. Y., assignor to Brooklyn,

Application March .21, 1942, Serial No. 435,625 12 Claims. (Cl. 332-204) This invention relates to a gyro flux valve compass system in which control over a directional gyro instrument is exercised by an earths fieldresponsive ilux valve.

An object of the invention is to provide a system o! this character that maintains oriented relationship between thecontrolling and controlled types of instruments employed.

An important feature of the invention resides in the lise oi' a rotatably mounted ilux valve instrument which is positioned in azimuth by a distantly located directional gyro through electrical controlling means therefor,

A further feature of the invention consists in the incorporation in the system of one or more repeater Compasses which are positioned in azimuthal agreement with the iiux valve-controlled directional gyro. l

Another important feature oi the invention resides in the utilization of means responsive to a variation in the output of the flux valve due to a change in the azimuthal position of the same in the earths neld for effecting the desired control over the directional gyro instrument.

A still further feature ci' the invention consists in the mounting arrangement by which the ux valve element is rotatably positioned in azimuth and controlled by an electrical repeater.

Other objects, features and structural details of the invention will be apparent from the following description when read in connection with the accompanying drawing, wherein Fig. l is a partial wiring diagram and schematic View showing the component parts of the system and the electrical connections employedthereior.

Fig. 2 is a further schematic view showing in perspective the improved mounting for the ilux valve and in sidetelevation the interior construe tion of the directional gyro, and

Fig. 3 is a complete wiring diagram of the system as embodied in both Figs. 1 and 2.

In the drawing, Fig. 2, I show a flux valve oi K the two legged type employed as the controlling element of the improved gyro compass system. A ilux valve of this kind is utilized in an illustrative manner only and it will be understood that the invention is not limitedin use to a system employing this speciilc type of ilux valve. Reference may be made to the copending application of Lennox F. Beach, illed July 31, 1941, Serial No. 404.809, in which there appears a complete description of the construction and operation of a two legged ilux valve. In this invention, the flux valve comprises circularly shaped ileld collectors Il, mounted on the respective ends of a straight magnetic ilux conducting core Ii. Situated midway between the collectors l0 and encircling the core il is a coil element designated generally at l2. The coil element is constructed to include, in thisinstance, the opposed exciting or primary windings i3 and i4, Fig. 3, for the ilux valve conipass instrument, the same being energized from a suitable source of alternating current energy as indicated at l5. The controlling output of the ilux valve is obtained from the secondary or pick up winding indicated at i6. In Figs. 1 and 3 of the drawing, the flux valve or flux Valve compass unit, as described, is designated by the reference number l1.

It will be understood that the output of 'the type of ux valve described varies as the instru ment rotates in azimuth in the earths magnetic eld. When the core i I is in a, north-pointins,r position the output of the valve is at one of its maximum values and a variation or deviation. of the compass from this position results in a de crease in the output of the instrument. Starting from a. north-pointing position of the chosen type oi flux valve and rotating the flux valve counter clockwise, the output decreases until a point oi zero output is reached as the valve passes through a west-pointing azimuthal position. 'Upon further rotation of the valve in the same direction, the phase ot the output reverses and the output increases again until a south-pointing position of the valve is reached, in which position it is at the other of its maximum values but opposite in phase to that at the assumed starting position. Further movement oi.' the ilux valve is similar 1n character to that described, the phase of the output reversing as thefiux valve passes through an east-pointing position and the output then in creases until the starting position is reached. In accordance with the teaching of the present invention, the axis of core Il, in normal operating position, lies in` an east-west plane, and the controlling flux valve is ineffective as long as the inuenced oriented relation exists betweenit and a controlled'instrument in the form of a directional gyro as indicated generally at i8 in Fig. l

and there is continuity in the 'output of the com-4 pass. The system is rendered effective in response to a variation in the output of the ilux valve due to a change in the azimuthal position of the same in the earths field. Electrical means are included in the system whereby the rotatably mounted flux valve is maintained in oriented relation with the directional gyro instrument as hereinafter more particularly described.

The ilux valve Il is rotatably mounted in a horizontal plane as shown in Fig. 2. This mounting includes an azimuthal position repeater whose casing is indicated at 20. The rotor oi' the electrical repeater has an extending shaft 2| to which the core Ii of the ilux valve is fixed by means of the V-shaped connecting arms 22 which are constructed of relatively impermeable or nonmagnetic material. Shaft 2| is located in a normally vertical position and the ilux valve is mounted to move with the same. A universal mounting consisting oi outer gimbal ring 23 and inner gimbal ring 24, whose respective axes are arranged in mutually perpendicular relation, is provided for the compass or flux valve and the repeater, the same being pendulouslv supported therein by means of the three extending arms 25, in this instance, which connect the inner gimbal ring 24 and the casing 20 of the electrical repeater. The arms 25 extend from a ring shaped piece which engages the casing 2u of the repeater and are joined at their equidistantly spaced opposite ends to the bottom of the inner gimbal ring 24.

Means for damping the mounting are provided in the present instance by dash pot members 90 and 3i. Slip ring connections may be employed as shown in Fig. 2 on the shaft 2l to permit the exciting energy for the flux valve unit to be introduced therein, to permit the output signal to be led therefrom and to enable the required energy to be supplied to the winding of the rotor for the repeater. The leads to the slip rings are made nexible and the weight of the same is negligible when compared with the weight of the repeater casing 2li which acts as a pendulous weight in the provided mounting.

The ux valve controlled instrument is a directional gyro of conventional form as shown in Fig. 2. The casing of the directional gyro, as herein illustrated, is provided with a window 35, and withinsaid casing is located a vertical ring 3| which is pivotally mounted on a vertical axis by means oi'trunnions 32 and 33. A compass card 34 is situated on the vertical ring 3l and is observable through the window 35 in the casing 30 which encloses the operating parts of the instrument. The sensitive element or gyro rotor (not shown) oi the instrument is mounted within a rotor bearing case 38 which in turn is pivotally mounted on a horizontal axis on the vertical ring 3i by means of trunnions 31 and 38. The spin axis of the gyro rotor is normal to the plane of the paper, as viewed in Fig. 2, the position of the same being indicated by the extending shaft 33. In the form of directional gyro instrument illustrated, the gyro rotor is spun electrically by a suitable driving motor (not shown) provided within the rotor bearing case 3B. Alternating current energy is provided to spin the gyro rotor from the source I5 by way of a jack connection 30' and cooperating groups ofl slip rings 40 and 4I which are respectively located on trunnions 33 and 3B. I

The control of the flux valve I1 over the directional gyro I3 is exerted through a precessing means for changing the azimuthal position oi' the gyro shown by the compass card 34 or the position oi' the vertical ring 3| with respect to the earths magnetic field. The precesslng means m conventional manner exerts a torque about the horizontal axis oi `the gyro rotor bearing case 34 and consequently effects a desired movement of the vertical ring 3i. The precessing means is electromagnetic, in the instant case, the same including permanent magnet elements 42 which are ilxed in position on the rotor bearing case 34 and a stationary centrally located coil 43 which encircles the vertical ring 3| of the instrument and is ixed to the interior surface of the case 30. Control over the precessing means for the directional gyro instrument may be exerted by the flux valve I1 through a phase sensitive amplifier of conventional form and indicated generally at 53. Other devices of similar character or means responsive to a variation in the output oi the flux valve I1 due to a change in the azimuthal position of the same in the earths field to ob tain the desired result may be employed in this connection without departing from the inventive concepts herewith disclosed. In the present instance, the output oi phase sensitive amplier il controls the direction o! the magnetic field set up by the coil 43 and hence determines the direction in which the precession-ei'lecting torque is applied, the same resulting in a movement oi the vertical ring of the directional gyro which will restore the flux valve to its original position in azimuth or to that position irom which the change in continuity of the output oi the nux valve, which resulted in the operation of the system, started. As shown in Figs. l and 3, the phase sensitive amplifier may be energized from the current source l5 through a suitable frequency doubler element indicated at ll. A suitable amplifier circuit may be employed which obviates the need of the frequency doubler 5I, if desired. The output of the secondary winding Il of the nux valve I1 is led to the phase sensitive amplifier 50 by way of leads 60 and 4I. Leads 62 and 6l connect the source IB and `frequency doubler 5I employed, in this instance. and leads 64 and l5 connect the primary or exciting windings of the i'lux valve with the source II. 'I'he output oi the phase sensitive ampliiler 50 is led to coil 43 of the gyro-precessing means by way of leads 86 and 61. Leads I8, 69 and 10 from the source I5 are provided to supply the energy necessary to spin the gyro rotor of the directional gyro employed inthe instant System.

By way of example, the phase sensitive ampliiler, which may be employed in this invention, may comprise a circuit including two stages of voltage amplincation for gain and a phase oiscriminatlng stage which may include a twin triode tube to the plates of which is supplied alternating current energy from a suitable frequency doubler. The precessing coil 43 is connected across the plates of said tube. A full wave rectiner, which is connected to the source of alternating current energy employed to energize the exciting winding of the flux valve, and n. voltage doubler are preferably employed both to supply the direct current plate voltage for the ampliner tubes and also, through modulation by the energy from the said alternating current energy source, to supply double frequency alternat ing current energy, which will be of the same frequency as that oi' the output from the iiux valve, to the phase discriminating stage of the ampliiler.

The improved system further includes an elec trical means for maintaining an oriented relation between the preferably spaced directional gyro I8 and the ux valve I1. This means includes a position-indicating transmitterdesignated generally at 30, Figs. 1 and 3, and the repeater device whose casing is indicated at 2li. Other repeaters such as those indicated at Il and 32 may be included in this portion oi the system, the same being employed to position repeater compass cards designated at 33 and 34,

respectively, which are controlled by the directional gyro. The particular position-repeating means illustrated in the drawing is provided by a Selsyn transmitter and receiver arrangement which is energized'from a separate source of alternating current energy as indicated at 85. The transmitter "Selsyn 30 and the repeater Selsyns designated generally in the drawing by the reference numbers 8i, 82 and 20 have their respective rotor windings indicated at 80', 8|', 32' and 20 connected in parallel relation and energized in common from the source. The Y connected stator ywindings for each of the Selsyns B0, I, 82 and 20 are joined in parallel relation by suitable connecting leads such as lindicated at 1I, 12, and 13, the windings proper being shownat 80", Bl", 82", and 20", in Fig, 3. Leads 14 and 15 are provided for supplying energy from source 85 to the respective rotors 80', 3l', 82', and 20'. As should be well understood in the art, the

I rotor 20', 82', and'll, of this transmitter-receiver arrangement repeats the azimuth position, in this instance, of the transmitter rotor 80' which is determined by the position of the vertical ring 3l of the directional gyro. In the construction shown, trunnion 32 is adapted to extend exteriorly of the casing "has designated at 32', Figs. 1 and 3, and is directly employed to position the rotor 30' of the transmitter 80. Other means for accomplishing this purpose may obviously also be employed without departing from the present, inventive concepts. As previouslydescribed, the flux valve l1 is positioned in azimuth by means of the extending shaft 2| of the gyro position-repeating rotor 20' of the primary receiver of the arrangement. Also, the position of the repeater compass cards 83 and 84, controlled frornthe rotors 82' and 8i', repeat the azimuthal position of the flux valve-controlled directional gyro. The transmitter-receiverlarrangement described, or other equivalent devices for the purpose, tends to maintain the directional gyro and the flux valve in predetermined orientated relation.

If while the vehicle on which the system is utilized is maintaining a particular straight course output oi the ilux valve and through means of the phase-sensitive amplifier and its control over the gyro precessing means, a precessing torque being exerted on the bearing case 36 in adirection to correct the position of the vertical This change is then repeated back to the flux valve by way of the described transmitter-receiver arrangement to obtain the desired correction in the position of the compass.

As many changes could be made in the above construction and many apparently widely diierent embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A gyro ilux valve compass system comprising a iiux valve, means for rotatably supporting said flux valve, a directional gyro, precessing means for changing the azimuthal position of the gyro, electrical means controlled by the gyro and operable thereby in its azimuthal movement to position said rotatable iiux valve in azimuthal agreement therewith, and means responsive to the output of said flux valve for controlling said precessing means for the gyro, whereby said gyro through the electrical means Acontrolled thereby may restore the ux valve to its .original position if said iiux valve should depart therefrom.

2. A gyro ux valve compass system, as claimed in claim 1, in which said gyro controlled electrical means includes a repeater compass which is positioned in azimuthal agreement with the flux valve controlled directional gyro.

3. A gyro flux valve compass system, as claimed inclairn l, in which said precessing means is electromagnetic and the controlling means therefor includesa phase sensitive ampliiler.

4. A gyro flux valve compass system comprising a ilux valve. means for rotatably supporting saidk ilux valve, a directional gyro, precessing means for changing the azimuthal position of the gyro, electrical means for maintaining the divalve for controlling said precessing means for the gyro, whereby said transmitter-receiver electrical means may restore the flux valve to its original position if said ilux valve should depart therefrom.

5. A gyro ilux valve compass system, as claimed in claim 4, in which said precessing means is electromagnetic and includes a stationary coil for said directional gyro and the controlling means therefor includes a phase sensitive ampliiler the output of which is fed to the stationary coil.

6. A gyro flux valve compass system, as claimed in claim 4, lin which the electrical receiver includes an extending shaft on which the ilux valve is positioned, and the receiver and flux valve are pendulously mounted on a universal support.

7. A gyro ux valve compass system comprising a flux valve, means for rotatably supporting said flux valve, a directional gyro including a vertical ring and a gyro rotor bearing frame .pivotally mounted on a horizontal axis on said ring, a position repeating electrical transmitter-receiver arrangement for maintaining the gyro and ux valve inoriented relationship, means for positioning the transmitter from the vertical ring o! the gyro, means for correspondingly positioning the flux valve from therotor of the receiver, precessing means for changing the azimuthal position of the vertical ring of the gyro, and means responsive to the output of said flux valve for controlling said precessing means forl the gyro, whereby said transmitter-receiver arrangement may restore the flux valve to its original position if said flux valve should depart therefrom- 8. A gyro flux valve compass system, as claimed in claim 7, in which a repeater compass is also controlled from the transmitter of the transmitter-receiver arrangement.

9. A gyro flux valve compass system, as claimed in claim 4, in which the electrical means for maintaining the directional gyro and ux valve in oriented relationship is provided by a Selsyn" transmitter-receiver arrangement.

10. The combination of a nux valve, an asimuthal position, electrical, repeater having a vertically extending rotor shaft on which the ux valve is xed, and a universal support in which the repeater and flux valve are pendulously mounted.

ll. 'I'he combination of a flux valve, an azimuthal position, electrical, repeater having a vertically extending rotor shai't on which the ilux o valve is mounted for movement therewith, a universal mounting, and means for connecting the repeater to the universal mounting whereby `said repeater and the ux valve therewith are pendulously supported.

l2. A gyro flux valve compass system comprising a nux valve, means for rotatably supporting said iiux valve, a directional gyro, precessing means for moving the gyro in azimuth, electrical means controlled by the gyro and operable thereby in its azimuthal movement to move said iiux valve in azimuth, and means responsive to the output o! said tlux valve for controlling said gyra-precessing means, whereby a predetermined azimuthal orientation oi said flux valve and gyro 10 will be maintained.

ROBERT S. CURRY. Jl. 

